BCIT Citations Collection | BCIT Institutional Repository

BCIT Citations Collection

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Collection of published works from BCIT researchers, faculty, and instructors.

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Spinal cord injury and type 2 diabetes
Objective: The objective of this study was to evaluate the association between spinal cord injury (SCI) and type 2 diabetes in a large representative sample and to determine whether an association exists irrespective of known risk factors for type 2 diabetes. Methods: Data were obtained on 60,678 respondents to the Statistics Canada 2010 Cycle of the cross-sectional Canadian Community Health Survey. Multivariable logistic regression, incorporating adjustment for confounders and probability weights to account for the Canadian Community Health Survey sampling method, was conducted to quantify this association. Results: After adjustment for both sex and age, SCI was associated with a significant increased odds of type 2 diabetes (adjusted odds ratio = 1.66, 95% confidence interval 1.16–2.36). These heightened odds persisted after additional adjustment for smoking status, hypertension status, body mass index, daily physical activity, alcohol intake, and daily consumption of fruits and vegetables (fully adjusted odds ratio = 2.45, 95% confidence interval 1.34–4.47). Conclusions: There is a strong association between SCI and type 2 diabetes, which is not explained by known risk factors for type 2 diabetes., Peer-reviewed article, Published. Received May 14, 2013 ; Accepted August 21, 2013.
Spinal cord injury influences psychogenic as well as physical components of female sexual ability
Study Design: Secure, web-based survey. Objectives: Elicit specific information about sexual function from women with spinal cord injuries (SCI). Setting: World-wide web. Methods: Individuals 18 years or older living with SCI obtained a pass code to enter a secure website and then answered survey questions. Results: Bladder and/or bowel incontinence during sexual activity and/or sexual intercourse were significant concerns and prevented some women from seeking sexual activity. Autonomic dysreflexia (AD) during sexual activity was interpreted negatively by many and was found to interfere with sexual activity. Most subjects reported difficulty becoming psychologically aroused as well as physically aroused, which were both correlated with feeling that their SCI had altered their sexual sense of self. An inverse relationship existed between developing new areas of arousal above the level of lesion and not having sensation or movement below the lesion. The most commonly reported sexual stimulation leading to the best arousal involved stimulation of the head/neck and torso areas. The majority of subjects reported having experienced intercourse postinjury. Most participants reported difficulty with positioning during foreplay and intercourse, vaginal lubrication, and spasticity during intercourse. Almost half reported experiencing orgasm postinjury and this was positively associated with the presence of genital sensation. Conclusion: SCI significantly impairs psychological and physical aspects of female sexual arousal. In addition, bladder and bowel incontinence as well as AD negatively impact sexual activity and intercourse., Peer-reviewed article, Published.
A state-of-the-art on concrete repairs and some thoughts on ways to achieve durability in repairs
Thee aim of this chapter is to provide the reader with a general overview of the different phenomena and factors involved with durability of repair and suggest the major aspects which the repair design should focus on. However, it is important to keep in mind that any repair problem needs to be addressed as a unique problem first, and the designer, by developing awareness of the several challenges involved, should be able to make mindful choices, adequate to the specific application that is being considered., Book chapter, Published.
Stochastic dynamics of gene expression in developing fly embryos
Proceedings of 2017 International Conference on Noise and Fluctuations (ICNF), Vilnius, Lithuania on 20-23 June 2017. Segmentation of the developing insect body is preceded by cell-specific gene expression. In fruit flies (Drosophila), pair-rule genes are expressed in spatial stripes specifying segment fates. Transcription of the even-skipped (eve) pair-rule gene was recently shown to proceed in noisy bursts. Here, we develop a stochastic model of eve transcription from DNA to mRNA. This indicates that eve transcription proceeds at two rates, with a slow rate providing basal production and a fast rate allowing for high mRNA output. This two-rate transcription may afford more reliability in mRNA output, and therefore the protein levels which specify cell type, than a simple on-off (one-rate) mechanism., Conference paper, Published.
Storage and the shift to low carbon energy
This work looks at the impact of assumptions made regarding efficiency of storage systems used with variable energy resources and how this applies to a solar PV installation. To find the optimal storage system to work with the cyclic solar output, a linear optimization model is implemented using OSeMOSYS. With 100% efficient, free storage, with no capacity restrictions, it is possible to get down to almost 5 GW of required solar installed capacity, but it requires 1.1 TWh of 100% efficient storage. Existing pumped hydro storage facilities have efficiencies between 70 and 80%, which increase these numbers to 7 GW and 1.2 TWh. With a storage model based on the worlds largest pumped hydro facility between 20 and 25 GW of installed solar capacity are required plus between 15 and 30 GWh of storage capacity to meet the 1 GW load. The capital infrastructure required to allow a solar installation to meet that of a baseload plant is therefore around an order of magnitude larger than what is commonly assumed. A shift away from fossil fuels to renewable/variable energy resources will require more infrastructure than indicated by simply considering the capacity factor of the energy source., Peer-reviewed article, Published. Manuscript received September 30, 2014; revised January 18, 2015.
Strengthening of timber beams using externally-bonded sprayed fibre reinforced polymers
The use of Fibre Reinforced Polymers (FRP) has grown in popularity in the construction industry. FRP has proven useful in the retrofit of various types of structural elements. It may be used for the strengthening of beams, the seismic upgrade of walls panels, as well as the jacketing of columns to provide confinement. There exist several methods of FRP application for the case of structural retrofits. These include the application of pre-prepared FRP mats, or application of FRP via the wet lay-up process. However, a new technique developed at the University of British Columbia allows for the application of FRP in the form of a spray. Externally bonded Sprayed FRP (SFRP) is known to increase strength and energy absorption capacity of a retrofitted member as well as, or better than, FRP sheets. However, tests have primarily been carried out on concrete members only. An area of interest, into which not much research has been conducted, is the application of SFRP to timber. Timber bridges are extensively used in many parts of the world. Often due to remoteness and practical constraints, it is impossible to apply FRP sheets to retrofit these bridges. SFRP would be a much easier method of FRP application. This study looked at the application of SFRP to Douglas Fir (D.Fir) Beam specimens subjected to 3-Point Flexural Loading only. The specimens were treated with either a water based (Borocol) or oil borne (Creosote) antifungal preservative prior to being sprayed with FRP. Different combinations of adhesives/bonding agents including Hydroxymethylated Resorcinol and Polymeric Isocyanates were used to try to develop a strong bond. When considering using only chemical adhesives to obtain a proper bond between the two constituents of the composite, use of HMR is recommended for timber which is untreated or has been treated with a water borne preservative such as Borocol, while a pMDI adhesive such as AtPrime 2 is recommended for timber treated with an oil borne preservative such as Creosote. For Non Creosoted beams, adhesives did not generate as significant of a strength gain. For Creosoted beams, adhesives may be sufficient to generate significant strength gain when SFRP is applied to a beam. Considering that most structures in use would probably have been treated with a preservative similar to Creosote, in practice, AtPrime 2 or some other some sort of pMDI would probably be the adhesive of choice. Based on the results of the study, it is possible to say that the application of SFRP to retrofit/rehabilitate timber structures shows considerable promise. If a decent bond is achieved between the composite constituents, it is possible to substantially increase the ultimate flexural strength of the member, as well as drastically increase its ductility and energy absorption capacity. It is recommended that further tests be carried out using different types of loading schemes, geometrical configurations of SFRP, other types of anchorage, and development of a proper analytical model before the method is adopted for widespread use., Thesis, Published.
Structured documents
Proceedings of 2012 European Intelligence and Security Informatics Conference (EISIC) in Odense, Denmark 22-24 Aug. 2012. Much of the information exchanged between agents over a network is encapsulated in XML documents. An XML document has a tree structure, and the meaning of the document can be understood in terms of a set of label-value pairs. The content of a document is often secured through digital signatures applied to different sections, while the document is passed between several agents. In this paper, we illustrate that this process is insecure in the sense that a malicious agent can deceive an honest agent to hold beliefs that are untrue. We provide a formal framework for analyzing the security of structured documents, based on the implicit epistemic impact that a signed document will have on a recipient. This kind of analysis can provide significant insight into deception and fraud detection., Conference paper, Published.
Student emotions with an edu-game
Proceedings of 2013 Humaine Association Conference on Affective Computing and Intelligent Interaction, Geneva, Switzerland, 2-5 Sept. 2013. We present the results of a study that explored the emotions experienced by students during interaction with an educational game for math (Heroes of Math Island). Starting from emotion frameworks in affective computing and education, we considered a larger set of emotions than in related research. For emotion labeling, we employed a standard method that relies on trained judges to report emotions over 20-second intervals. However, we asked judges to report all observed emotions in each interval, as opposed to only choosing one, as is standard practice. This variation allows us to discuss the appropriateness of this interval for emotion labeling. We present a detailed analysis of inter-coder reliability, both aggregated and over individual students, that considers not only the matching by judges over emotion type, but also the number of emotions detected., Conference paper, Published., Peer reviewed
Students use new lab to test electrical and cybersecurity systems
2016 | 2017 Project Highlights Short piece about BCIT Smart Microgrid designs., Article, Published
Study on the mechanical and environmental properties of concrete containing cathode ray tube glass aggregate
Cathode ray tube (CRT) glass is considered a hazardous material due to its lead toxicity. In addition, current disposal practices are being phased out due to their adverse environmental impacts. In this project, CRT glass was used as a fine aggregate replacement in concrete. Life-cycle material characterization was conducted by evaluating the durability and strength of the CRT-Concrete. Leaching tests were also conducted to investigate whether the material meets drinking water limits for Pb. Test results show that the plastic state of the CRT-Concrete was affected by the angularity of the glass particles. Moreover, the compressive strength of CRT-Concrete met and exceeded that of the control specimen. However, CRT-Concrete was susceptible to expansive alkali-silica reactions when more than 10% CRT replacement was used. Environmental leaching results show that lead concentrations from CRT-Concrete are below the drinking water limits depending on the CRT volume replacement and if biopolymers are used., Peer reviewed, Peer reviewed article, Received 26 July 2012 ; Accepted 24 March 2013 ; Available online 28 April 2013., Durability, CRT, Heavy metals, Glass recycling, Waste management, Sustainable concrete
Suppression of positional errors in biological development
Cells in developing embryos behave according to their positions in the organism, and therefore seem to be receiving `positional information'. A widespread view of the mechanism for this is that each cell responds locally to the concentration level of some extracellular chemical which is distributed in a spatial gradient. For molecules conveying and receiving the positional signal, concentrations are likely to be low enough that, per individual cell, only a few thousand molecules may be involved. Fluctuations to be expected in these numbers (Poisson distribution) could readily lead to errors up to a few percent of embryo length in the reading of position. This is an intolerable level of error for some developmental pattern-forming events. Embryos must have means of suppressing such errors. We maintain that this requires communication between cells, and illustrate this by using the reaction part of two well-known Turing-type reaction–diffusion models as the local gradient reader. We show that switching on diffusion in these models leads to adequate suppression of positional errors., Peer-reviewed article, Published. Received 31 December 1997, Revised 20 July 1998, Accepted 21 July 1998, Available online 24 March 1999.
Suppression of Rho-kinase activity promotes axonal growth on inhibitory CNS substrates
Several molecules inhibit axonal growth cones and may account for the failure of central nervous system regeneration, including myelin proteins and various chondroitan sulfate proteoglycans expressed at the site of injury. Axonal growth inhibition by myelin and chondroitan sulfate proteoglycans may in part be controlled by Rho-GTPase, which mediates growth cone collapse. Here, we tested in vitro whether pharmacological inhibition of a major downstream effector of Rho, Rho-kinase, promotes axonal outgrowth from dorsal root ganglia grown on aggrecan. Aggrecan substrates stimulated Rho activity and were inhibitory to axonal growth. Y-27632 treatment promoted the growth of axons by 5- to 10-fold and induced “steamlined” growth cones with longer filopodia and smaller lamellipodia. Interestingly, more actin bundles reminiscent of stress fibers in the central domain of the growth cone were observed when grown on aggrecan compared to laminin. In addition, Y-27632 significantly promoted axonal growth on both myelin and adult rat spinal cord cryosections. Our data suggest that suppression of Rho-kinase activity may enhance axonal regeneration in the central nervous system., Peer-reviewed article, Published. Received 2 July 2002; Revised 24 October 2002; Accepted 28 October 2002; Available online 23 March 2003.
Synthesis of galactofuranosyl-containing oligosaccharides corresponding to the glycosylinositolphospholipid of Trypanosomacruzi
The oligosaccharide β-d-Galf-(1→3)-α-d-Manp-(1→2)-[β-d-Galf-(1→3)]-α-d-Manp-(1→2)-α-d-Manp corresponds to the terminal end of the glycosylinositolphospholipid oligosaccharide of the protozoan Trypanosomacruzi, the causative agent of Chagas’ disease. Syntheses of methyl or ethylthio glycosides of the terminal disaccharide, trisaccharide, tetrasaccharide, and pentasaccharide corresponding to this structure are described. These syntheses employ the selective activation of a phenyl 1-selenogalactofuranoside or a phenyl 1-selenomannopyranoside donor over ethyl 1-thioglycoside acceptors with NIS–TfOH., Peer-reviewed article, Published. Received 8 December 1999; Accepted 14 December 1999; Available online 19 April 2000.
Taxonomizing features and methods for identifying at-risk students in computing courses
Proceedings from the 23rd Annual ACM Conference on Innovation and Technology in Computer Science Education. Since computing education began, we have sought to learn why students struggle in computer science and how to identify these at-risk students as early as possible. Due to the increasing availability of instrumented coding tools in introductory CS courses, the amount of direct observational data of student working patterns has increased significantly in the past decade, leading to a flurry of attempts to identify at-risk students using data mining techniques on code artifacts. The goal of this work is to produce a systematic literature review to describe the breadth of work being done on the identification of at-risk students in computing courses. In addition to the review itself, which will summarize key areas of work being completed in the field, we will present a taxonomy (based on data sources, methods, and contexts) to classify work in the area., Peer reviewed, Conference paper, Published.
Temperature and air flow patterns in attic roofs
Understanding temperature and airflow patterns in an attic roof helps to identify the sections of the roof where moisture damage and roofing material durability problems can be expected. In this paper, the temperature distribution and the airflow patterns inside an attic space in a climate that can be characterized with cold winter and hot summer periods are discussed. In the study, transient boundary conditions were applied, and the dynamic responses of a typical attic roof, including the flow patterns, attic air and roof sheathing temperatures, ventilation rates, and heating and cooling loads, are presented. These findings can be used to understand the airflow pattern and how it can be affected by an incoming wind speed and solar gain., Peer reviewed article, Published. Received: September 14, 2016; Accepted: March 08, 2017; Published online: June 22, 2017.
Temperature and humidity distributions in mid-rise residential building suites
14th Canadian Conference on Building Science and Technology, Toronto, Canada, October 29th-30th, 2014. It is essential to design and operate buildings with good indoor air quality as people spend most of their time indoor. Their productivity, comfort and health depend on the quality of the indoor air. In addition to other air quality parameters, indoor humidity and temperature need to be controlled and maintained to acceptable ranges. These conditions may not be uniform within the house/building due to local heat and moisture sources and absence of an effective indoor air mixing mechanism as in the case of in buildings with baseboard heating systems. Localized high humidity creates favourable conditions for localized mold growth, poor indoor air quality and building envelope damage. In this paper, the indoor humidity and temperature distributions within four suites (designated as Suite ‘A’, ‘B’, ‘C’ and ‘D’) in a six-storey multi-residential building are studied. A total of 22 rooms are monitored with indoor temperature and relative humidity data loggers, and the outdoor climatic conditions are measured with a weather station for over a year. The hygrothermal performances of exterior walls in the master bedrooms of the respective suites are assessed. Analysis of the measured data suggests that the temperature variations between the rooms (bedrooms, living room, kitchen excluding bathroom) are relatively low during the summer period (mean temperature difference less than 1oC) compared to the winter period where the variations between the rooms can be as high as 2oC. The excess humidity differences between the rooms, excluding the kitchens, are in the range of 0.2 g/m 3 to 1.0 g/m 3 during both winter and summer periods, whereas the excess humidity fluctuations within the rooms are fairly the same and have standard deviation values between 0.8 g/m 3 and 1.0 g/m 3. Excess humidity is defined as the difference between the indoor and outdoor absolute humidities, quantities that are derived from the simultaneously measured temperature and relative humidity of the indoor and outdoor locations. Hygrothermal simulation results of exterior wall systems indicate that, in a mild coastal climate, the winter average indoor relative humidity shall be below 43% (for a seasonal average indoor temperature of 20oC) to avoid building envelope moisture damage., Peer reviewed article, Published.

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